The present invention relates to data center infrastructure, and more particularly, this invention relates to Ethernet switches capable of unregistered Multicast Control (MC) packet switching.
In packet-switched network switches, look-up is typically performed on a destination media access control (MAC) address or a destination Internet protocol (IP) address to discover an actual destination port for forwarding the packet. Most systems utilize a switching processor of some kind, such as an application specific integrated circuit (ASIC). In operation, the conventional switching processor forwards unregistered IP multicast data packets to a multicast router port. The multicast router port is typically acquired via an Internet Group Multicast Protocol (IGMP) query, protocol independent multicast (PIM) hello message(s), or is preconfigured on a virtual local area network (VLAN) when multicast flooding is disabled in the switch.
Unfortunately, conventional MC switching protocols such as Internet Protocol Multicast Communications (IPMC) switching protocols suffer from two primary disadvantages. First, unregistered multicast data traffic is trapped continuously to a central processing unit (CPU) until multicast router ports are learned or programmed in the hardware. This keeps the CPU busy processing packets, disadvantageously consuming network and system resources.
A second disadvantage of the conventional IPMC switching protocols is that separate entries must be added for each multicast group for which data traffic is received on a particular VLAN.